The present invention relates to a method of and apparatus for setting up boxes. More particularly this invention concerns a system that takes flat essentially two-dimensional box blanks and erects them into three-dimensional boxes ready for filling.
A box blank typically has a plurality of coplanar panels and flaps that are separated by fold lines. Such blanks are delivered to the user in this flat form so they are easy to handle and ship. The user in turn sets them up into the desired three-dimensional shape normally by means of an automatic apparatus that delivers them to an assembly line where they are, for instance, filled.
The setting-up machine receives the flat blanks from a supply, holds it with grippers, and pushes it into shape with various tools. Invariably this procedure is done as the blank travels along a treatment path from the supply to the station where the boxes are filled. To this end the setup tools must of course move perpendicular to the direction of travel of the blank, necessitating some complex coordination of the various conveyors and actuators.
In intermittently operating machines, where the blank is moved in steps through the setup apparatus, each setup tool must move inward transversely of the travel direction into engagement with the blank and then outward completely out of contact with it before the blank can be moved to the next setup station. As a result the blank""s travel through the machine is fairly slow, and the equipment is expensive and complex.
In a somewhat faster system there are no transversely displaceable setup tools. Instead the blank is pushed through a set of intricately shaped guides that fold portions sequentially until the desired final shape is achieved. Such a system does not form an accurately shaped box unless an expensive precreased blank is used. In addition sliding the blanks along these guides can scratch the surface of the box, something that is not acceptable when the box has a glossy finish.
German patent document 1 198 664 of Robert Leslie Agar and U.S. Pat. No. 5,269,741 of Wilhelm Fischer describe such systems. Here some of the shaping tools are movable with the workpiece, but much of the folding is done by stationary rails that press against the workpiece. Thus the workpiece slides over these stationary folding rails and, as a result of the relative movement between the blank and the rails, the blank""s finish is susceptible to damage as mentioned above. Both systems are also quite complex and extremely difficult to set up to work with blanks of different dimensions.
It is therefore an object of the present invention to provide an improved system for setting up box blanks.
Another object is the provision of such an improved system for setting up box blanks which overcomes the above-given disadvantages, that is which surely, rapidly, and accurately sets up box blanks without damage to their finish.
Flat box blanks are set up into boxes according to the invention by feeding a succession of the blanks one at a time to a setup station and gripping the blanks and pulling them one after another by means of grippers in a direction without stopping through the station. A plurality of setup tools are moved through the station in the direction synchronously with the grippers and the blanks and are engaged with the continuously moving setup tools transversely with the blanks in the setup station to shape the blanks into boxes while the blanks are held out of contact in the station with any structure other than the synchronously moving tools and grippers.
Thus with this system the tools and grippers all move with the blanks. Thus they can accurately fold them into boxes without marring their finish. Even relatively complex folding operations, as for instance needed to tuck side-panel end flaps inside the front and back panels, can be carried out accurately and with ease by the moving tools as they travel with the workpieces through the setup station. Since the blanks never stop moving, the apparatus can operate fairly rapidly, producing setup boxes at a great rate.
The apparatus for setting up flat box blanks into boxes has according to the invention a supply or magazine for feeding a succession of the blanks one at a time to a setup station, at least one gripper for gripping the blanks and pulling them one after the other in a direction without stopping through the station, and a plurality of setup tools displaceable in the station transversely of the direction for engaging the blank held in the gripper and passing through the station and folding it into a box. A transport system is connected to the setup tools for displacing them in the direction synchronously with the gripper as the tools fold the blank held by the gripper into a box.
The tools in accordance with the invention include fluid-powered actuators. In addition the transport system includes at least one endless conveyor element having a stretch extending in the direction through the machine and the tools and gripper are mounted on the element. Normally according to the invention a plurality of sets of the tools and respective grippers are mounted on the element. In fact for most efficient operation two such elements flank a path extending in the direction through the station and each such element carries a plurality of sets of tools and respective grippers. To accommodate blanks of different sizes a spacing between the tools in the direction and a spacing between the stretches transverse to the direction can be varied.
The tools include two front tools and two back tools spaced in the direction from the front tools. As the transport element is advanced the front tools precede the back tools.
The system of this invention may also be provided with means for applying an adhesive to flaps of the blank and means for taking set-up boxes from the gripper at a downstream side of the station. The tools themselves have means for stripping set-up boxes from themselves. The apparatus can also have means for closing top panels of the boxes and for feeding objects to be packaged to the station which are set up around the objects to be packaged.